In the manufacture of enclosures, it is a purpose of the invention to especially eliminate the setting times (setting need) relating especially to the folding and, simultaneously, to increase the flexibility of production so that the principal dimensions of the enclosure can be chosen freely (continuously). This increases considerably the possibilities of the enclosure manufacturer to customise the enclosure exactly according to the needs of the customer without an essential increase in the manufacturing costs in the form of tools to be obtained for special purposes and of setting times.
Another aspect that is simultaneously developed in the invention is the shape of the initial blanks. Because the common practice and starting point for the blank shape is a star blank, other alternatives for initial blanks i.e. sheet blanks are also the so-called L, T, S and H blanks, the advantage of which is to be seen in the possibility to more efficiently use the raw material, due to the bigger “empty” space and the better nesting of the blanks to the raw material sheet in relation to waste material. An enclosure of a sheet material can be made of any suitable material. It is essential that permanent deformation can be achieved to the material by folding, without causing any breakages to the material that could be considered damage. Materials suitable for this purpose, together with their different mixtures are, for example, several types of sheet material, steels, aluminium, copper, brass, certain plastics, etc.
DE 100 20 068 A1 is known from the state of the art, disclosing a method for manufacturing a box of a sheet material. In this publication, the folding lines are perforated so that it would also be easy to do the folding manually.
Also U.S. Pat. No. 6,412,325 B1 is known from the state of the art; here the folding lines of a blank of a box of a sheet material are also perforated before the folding of the actual box.
Also Patent Abstracts of Japan, publication number JP 09141333A is known from the state of the art; here a V-shaped folding slot is respectively processed to the folding line. In this case, the folding is easy, but the structure will stay intact, contrary to the folding of perforated sheets when there are perforation holes throughout the whole range of the fold.
The other solutions previously known have been based on the reduction of setting times with a robotised folding machine or on a completely automated folding machine. As solutions, these are more expensive, and they are based on the automated setting of tools and on the automated change of tools, not on the removal of the setting need itself. In the automated solutions, the initial blank used is typically a star blank, or a loose casing and base.
In the reduction of setting times, weaknesses of the said prior art automated systems are, among others, their price and dimensional restrictions. A continuous length of the folding seam is difficult to achieve, and as a tool covering the whole folding length needed, it is in practice almost impossible to realise in a rational manner. In addition, as the folding is in these cases made by a folding machine or a robot suitable for the purpose instead of a human-being, this will take time in any case.